Flying close to ground troops in combat in hostile and high-threat conditions requires a host of unique attributes for an aircraft -- such as flying slow and low to the ground, absorbing some degree of small arms fire and having an ability to quickly maneuver in response to fast-changing ground combat conditions.

These, and many more, are among factors now being analyzed as proponents of both the A-10 Warthog and F-35 Joint Strike Fighter assess their respective abilities to perform the crucial and highly valued Close Air Support mission. The Pentagon and the Air Force are now conducting a thorough examination of each plane's capability for this role - including extensive analysis, simulated tests, flights of both aircraft under combat-like conditions and a range of tests, Air Force and Pentagon officials have explained. While many of the details of the ongoing evaluation are not now being discussed publically, the results are expected to bear prominently upon the visible ongoing debate regarding the future mission scope of both the A-10 and the F-35.

While the cherished A-10 is unambiguously combat-tested in the role of Close Air Support, some F-35 advocates have mused that the JSF sensors, maneuverability, high-tech computers and arsenal of weapons just might better position the 5th generation aircraft for the mission; at the same time, the A-10s titanium frame, built-in redundancy, famous nose-aligned 30mm cannon and wide-ranging precision-weapons envelope make clearly make it the best choice for close air support.

Sure enough, the A-10s performance against ISIS, Congressional lobby and broad adoration among ground troops are among the many factors believed to have influenced the Air Force's current plan to both extend the life of the current A-10 and also explore requirements options for a future Close Air Support platform. Air Force officials have told Scout Warrior the ongoing requirements and analysis procedure is looking at three options - upgrading the existing A-10 airframe, using the best available commercial-off-the shelf aircraft, or simply engineering an building a newly designed A-10-like Close Air Support airplane.

Many A-10 proponents are convinced that there is no other plane capable of succeeding with the highly-dangerous, revered and essential Close Air Support Mission. Nevertheless, the Air Force does plan to use the emerging F-35 for Close Air Support moving into the next decade. In addition, F-35 advocates argue that the stealth aircraft's speed, maneuverability and high-tech weapons and sensors give the F-35 a decisive Close Air Support advantage.

In the meantime, the F-35 weapons integration including live fire drops, weapons separation assessments and modifications for future munitions adaptions is progressing as well alongside the existing F-35/A-10 analysis.

So-called "Block 3F" software for the F-35 increases the weapons delivery capacity of the JSF as well, giving it the ability to drop a Small Diameter Bomb and 500-pound JDAM.

By the early 2020s, the F-35 is slated to be configured with a next-generation Small Diameter Bomb II

As a multi-role fighter, the F-35 is also engineered to function as an intelligence, surveillance and reconnaissance platform designed to apprehend and process video, data and information from long distances. Some F-35 developers have gone so far as to say the F-35 has ISR technologies comparable to many drones in service today that are able to beam a “soda straw” video view of tactically relevant combat locations in real time.

Built-in ISR is an asset which could have the effect of greatly helping close-air-support efforts.

Also, F-35 advocates reiterate that the airplane's high-tech Electro-Optical Targeting System and 360-degree sensors Distributed Aperture System will give the newer aircraft an uncontested combat and close-air-support ability. The F-35s so-called computer-enabled "sensor fusion" might enable it to more quickly ascertain and destroy moving targets by gathering, integrating and presenting fast-changing combat dynamics and circumstances.

Finally, the F-35's stealth configuration and speed is expected to better enable it to evade air defenses and move closer to emerging ground-targets in many instances -- and its air-to-air ability will enable the aircraft to respond to potential air-threats which could appear in the course of a ground-support mission.

AIM-9X Sidewinder Missile:

The F-35 Joint Strike Fighter fired an AIM-9X Sidewinder infrared-guided air-to-air missile for the first time in recent months over a Pacific Sea Test Range, Pentagon officials said.

The F-35 took off from Edwards Air Force Base, Calif., and launched the missile at 6,000 feet, an Air Force statement said.

Designed as part of the developmental trajectory for the emerging F-35, the test-firing facilities further development of an ability to fire the weapon “off-boresight,” described as an ability to target and destroy air to air targets that are not in front of the aircraft with a direct or immediate line of sight, Pentagon officials explained.

“If you think if a boresight in terms of a firearm… that’s the adjustments made to an optical sight, to align the barrel of a firearm with the sights. If you think of it in aircraft terms… traditionally air-to-air missiles are fired at targets in front of the them,” Joint Strike Fighter Program Office spokesman Joe DellaVedova, told Scout Warrior.

The AIM-9X, he described, incorporates an agile thrust vector controlled airframe and the missile’s high off-boresight capability can be used with an advanced helmet (or a helmet-mounted sight) for a wider attack envelope.

“For example, instead of having to position the aircraft directly in front or behind the enemy fighter… a high off-boresight weapon enables the pilot to just look to the left, right or up and down to engage a target, fire it and the missile locks on for the kill,” he explained.

The AIM-9X missile, which can also be fired at surface-to-air and air-to-surface, is currently in use on a number of existing fighter aircraft such as the Air Force’s F-15E and F-16 and the Navy’s F-18 Super Hornet.

Engineered by Raytheon, the newest AIM-9X Block II weapons are built with a redesigned fuse for increased safety and a lock-on-launch capability. The missile is also configured with a data link to support what’s called “beyond visual range” engagements, meaning targets at much farther ranges picked up by sensors or early warning radar. This could provide a fighter jet with an ability to destroy enemy targets in the air while remaining at a safer stand-off distance less exposed to hostile fire.

"The AIM-9X Sidewinder is an infrared-guided, air-to-air missile employing a focal plane array sensor for unparalleled target acquisition and tracking, augmented by jet vane control technology for extreme maneuverability against a variety of high performance threats,” Mark Justus, Raytheon AIM-9X program director, told Scout Warrior in a written statement. "The missile also has proven capability in air-to-surface and demonstrated capability in surface-to-air missions."

The AIM-9X Block II is the current version of the AIM-9 Sidewinder short range missile family in use by more than 40 nations throughout the world, Justus added.

"The AIM-9X missile has been acquired by twenty international partners. It is configured for easy installation on a wide variety of modern fighter aircraft and we are excited to complete this milestone of the first AIM-9X live fire from the F-35 as we progress through the aircraft/missile integration activities," he said.

Weapons integration for the F-35 is designed to evolve in tandem with software advances for the aircraft, described as “increments.” Each increment, involving massive amounts of lines of computer code, improves the platform’s ability to integrate, carry and fire a wider range of weapons.

Block 2B, for example, is already operational and builds upon the enhanced simulated weapons, data link capabilities and early fused sensor integration of the earlier Block 2A software drop.

Block 2B enables the JSF to provide basic close air support and fire an AMRAAM (Advanced Medium Range Air to Air Missile), JDAM (Joint Direct Attack Munition) or GBU 12 (laser-guided aerial bomb), JSF program officials have said.

The next increment, Blocks 3i will increase the combat capability even further and Block 3F will bring a vastly increased ability to suppress enemy air defenses.

The Air Force plans to reach operational status with software Block 3i in 2016. Full operational capability will come with Block 3F, service officials said.

Block 3F will increase the weapons delivery capacity of the JSF as well, giving it the ability to drop a Small Diameter Bomb, 500-pound JDAM and AIM 9X short-range air-to-air missile, Air Force officials said.

F-35 25mm Gatling Gun:

Last Fall, the Pentagon’s F-35 Joint Strike Fighter completed the first aerial test of its 25mm Gatling gun embedded into the left wing of the aircraft, officials said.

The test took place Oct. 30, 2015 in California, Pentagon officials described.

“This milestone was the first in a series of test flights to functionally evaluate the in-flight operation of the F-35A’s internal 25mm gun throughout its employment envelope,” a Pentagon statement said.

The Gatling gun will bring a substantial technology to the multi-role fighter platform, as it will better enable the aircraft to perform air-to-air attacks and close-air support missions to troops on the ground – a task of growing consequence given the Air Force plan to retire the A-10.

Called the Gun Airborne Unit, or GAU-22/A, the weapon is engineered into the aircraft in such a manner as to maintain the platform’s stealth configuration.

The four-barrel 25mm gun is designed for rapid fire in order to quickly blanket an enemy with gunfire and destroy targets quickly. The weapon is able to fire 3,300 rounds per minute, according to a statement from General Dynamics.

“Three bursts of one 30 rounds and two 60 rounds each were fired from the aircraft’s four-barrel, 25-millimeter Gatling gun. In integrating the weapon into the stealthy F-35A airframe, the gun must be kept hidden behind closed doors to reduce its radar cross section until the trigger is pulled,” a statement from the Pentagon’s Joint Strike Fighter said.

The first phase of test execution consisted of 13 ground gunfire events over the course of three months to verify the integration of the gun into the F-35A, the JSF office said.

“Once verified, the team was cleared to begin this second phase of testing, with the goal of evaluating the gun’s performance and integration with the airframe during airborne gunfire in various flight conditions and aircraft configurations,” the statement added.

The new gun will also be integrated with the F-35’s software so as to enable the pilot to see and destroy targets using a helmet-mounted display.

The gun is slated to be operational by 2017.

Small Diameter Bomb II:

The Air Force is engineering and testing a new air-dropped weapon able to destroy moving targets in all kinds of weather conditions at ranges greater than 40-miles, Air Force and Raytheon officials said.

The Small Diameter Bomb II, or SDB II, is designed to integrate onto the F-35 by 2022 or 2023; it is engineered todestroy moving targets in all kinds of weather, such as small groups of ISIS or terrorist fighters on-the-move in pick-up trucks.

A weapon of this kind would be of extreme relevance against ISIS fighters as the group is known to deliberately hide among civilian populations and make movements under cloud cover or adverse weather in order to avoid detection from overhead surveillance technologies.

While the Air Force currently uses a laser-guided bomb called the GBU-54 able to destroy moving targets, the new SDB II will be able to do this at longer ranges and in all kinds of weather conditions. In addition, the SDB II is built with a two-way, dual-band data link which enables it to change targets or adjust to different target locations while in flight.

A key part of the SDB II is a technology called a “tri-mode” seeker — a guidance system which can direct the weapon using millimeter wave radar, uncooled imaging infrared guidance and semi-active laser technology.

A tri-mode seeker provides a range of guidance and targeting options typically not used together in one system. Millimeter wave radar gives the weapon an ability to navigate through adverse weather, conditions in which other guidance systems might encounter problems reaching or pinpointing targets.

Imagining infrared guidance allows the weapon to track and hone in on heat signatures such as the temperature of an enemy vehicle. With semi-active laser technology, the weapon can be guided to an exact point using a laser designator or laser illuminator coming from the air or the ground.

Also, the SBD II brings a new ability to track targets in flight through use of a two-way Link 16 and UHF data link, Raytheon officials said.

The millimeter wave radar turns on first. Then the data link gives it a cue and tells the seeker where to open up and look. Then, the weapon can turn on its IR (infrared) which uses heat seeking technology, Raytheon officials said.

The SBD II is engineered to weigh only 208 pounds, a lighter weight than most other air dropped bombs, so that eight of them can fit on the inside of an F-35 Joint Strike Fighter, Raytheon officials explained.

Attack Missions in the A-10 - A Pilot's View:

Known for an ability to keep flying after taking multiple rounds of enemy machine gun fire, land and operate in rugged terrain, destroy groups of enemy fighters with a 30mm cannon and unleash a wide arsenal of attack weapons, the A-10 is described by pilots as a “flying tank” in the sky -- able to hover over ground war and provide life-saving close air support in high-threat combat environments.

“It is built to withstand more damage than any other frame that I know of. It’s known for its ruggedness,” A-10 pilot Lt. Col. Ryan Haden, 23rd Fighter Group Deputy, Moody AFB, told Scout Warrior in an interview.

The pilot of the A-10 is surrounded by multiple plates of titanium armor, designed to enable the aircraft to withstand small-arms fire and keep flying its attack missions.

“The A-10 is not agile, nimble, fast or quick,” Haden said. “It’s deliberate, measured, hefty, impactful calculated and sound. There’s nothing flimsy or fragile about the way it is constructed or about the way that it flies.”

A-10 Thunderbolt II, affectionately known as the Warthog, has been in service since the late 1970s and served as a close air support combat aircraft in conflicts such as the Gulf War, Operation Enduring Freedom, Operation Iraqi Freedom and Operation Allied Force in Kosovo, among others.

Having flown combat missions in the A-10, Haden explained how the aircraft is specially designed to survive enemy ground attacks.

“There are things built in for redundancy. If one hydraulic system fails, another one kicks in,” he said.

If the aircraft loses all of its electronics including its digital displays and targeting systems, the pilot of an A-10 can still fly, drop general purpose bombs and shoot the 30mm cannon, Haden explained.

“So when I lose all the computers and the calculations, the targeting pod and the heads up display, you can still point the aircraft using a degraded system at the target and shoot. We are actually trained for that,” he said.

Unlike other air platforms built for speed, maneuverability, air-to-air dogfighting and air-to-air weapons, the A-10 is specifically engineered around its gun, a 30mm cannon aligned directly beneath the fuselage. The gun is also called a GAU-8/A Gatling gun.

“The 30mm cannon has 7 barrels. They are centered the way the aircraft fires. The firing barrel goes right down the center line. You can point the aircraft and shoot at the ground. It is designed for air to ground attack,” Haden explained.

Armed with 1,150 rounds, the 30mm cannon is able to fire 70-rounds a second.

Haden explained the gun alignment as being straight along the fuselage line without an upward “cant” like many other aircraft have. Also, the windows in the A-10 are also wider to allow pilots a larger field of view with which to see and attack targets.

The engines of the A-10 are mounted high so that the aircraft can land in austere environments such as rugged, dirty or sandy terrain, Haden said. The engines on the A-10 are General Electric TF34-GE-100 turbofans.

“I’ve seen this airplane land on a desert strip with the main gear buried in a foot of sand. On most planes, this would have ripped the gear up, but the A-10 turned right around and took off,” he added.

There have been many instances where A-10 engines were shot up and the pilots did not know until the returned from a mission, Haden said.

These aerodynamic configurations and engine technology allow the A-10 to fly slower and lower, in closer proximity to ground forces and enemy targets.

“The wings are straight and broadened. The engines are turbofan. They were selected and designed for their efficiency, not because of an enormous thrust. We have a very efficient engine that allows me to loiter with a much more efficient gas-burn rate,” Haden said.

Close Air Support:

By virtue of being able to fly at slower speeds of 300, the A-10 can fly beneath the weather at altitudes of 100 feet. This gives pilots and ability to see enemy targets with the naked eye, giving them the ability to drop bombs, fire rockets and open fire with the 30mm cannon in close proximity to friendly forces.

“We shoot really close to people. We do it 50-meters away from people. I can sometimes see hands and people waving. If I get close enough and low enough I can see the difference between good guys and bad guys and shoot,” Haden explained.

The aircraft’s bombs, rockets and cannon attack enemies up close or from miles sway, depending on the target and slant range of the aircraft, Haden added.

“We deliver the munitions by actually going from a base position – then pointing the jet at the ground and then pulling the trigger once we reach the desired range,” he explained.

The A-10 uses both “Lightning” and “Sniper” pods engineered with infrared and electro-optical sensors able to find targets for the pilot.

“The aircraft uses the same targeting pod as F-15E and F-16. However, most of the fighters can’t transition between the two targeting pods and we can, based on our software,” Haden said.

The A-10 carries a full complement of weapons to include Joint Direct Attack Munitions, or JDAM GPS-guided bombs; its arsenal includes GBU 38s, GBU 31s, GBU 54s, Mk 82s, Mk 84s, AGM-65s (Maverick missiles), AIM-9 Sidewinder missiles and rockets along with illumination flares, jammer pods and other protective countermeasures. The aircraft can carry 16,000 pounds of mixed ordnance; eight can fly under the wings and three under-fuselage pylon station, Air Force statements said.

A-10 Avionics Technology:

Pilots flying attack missions in the aircraft communicate with other aircraft and ground forces using radios and a data-link known at LINK 16. Pilots can also text message with other aircraft and across platforms, Haden added.

The cockpit is engineered with what is called the CASS cockpit, for Common Avionics Architecture System, which includes moving digital map displays and various screens showing pertinent information such as altitude, elevation, surrounding terrain and target data.

A-10 pilots also wear a high-tech helmet which enables them to look at targeting video on a helmet display.

“I can project my targeting pod video into my eye so I can see the field of view. If something shoots at me I can target it simply by looking at it,” he explained.

Operation Anaconda:

During the early months of combat in Operation Enduring Freedom, in a battle known as “Operation Anaconda,” Haden’s A-10 wound up in a fast-moving, dynamic combat circumstance wherein U.S. military were attacking Taliban fighters in the Afghan mountains.

During the mission in March of 2002, Haden was able to see and destroy Taliban anti-aircraft artillery, guns and troop positions.

“We could see tracer fire going from one side of the valley to the other side of the valley. We were unable to tell which was from good guys and which was from bad guys. Using close air support procedures in conjunction with our sensors on board, we deconstructed the tactical situation and then shot,” he said.

Kris Osborn became the Managing Editor of Scout Warrior in August of 2015. His role with Scout.com includes managing content on the Scout Warrior site and generating independently sourced original material. Scout Warrior is aimed at providing engaging, substantial military-specific content covering a range of key areas such as weapons, emerging or next-generation technologies and issues of relevance to the military. Just prior to coming to Scout Warrior, Osborn served as an Associate Editor at the Military.com. This story originally appeared in Scout Warrior.